PROFIS ENGINEERING
Nominal Concrete Breakout Strength in Tension( N cbg)
N cbg =
A ACI 318-19 Eq.( 17.6.2.1b) Nc ψ A ec, N ψ ed, N ψ c, N ψ cp, N N b Nc0 h ef = 3.25 in 1.5h ef = 4.875 in 3.0h ef = 9.75 in
A Nc =( A Nc1 + A Nc2 + A Nc3 + A Nc4 + A Nc5 + A Nc6) A Nc1 =( 5.4 in)( 4.2 in) = 22.68 in 2 A Nc2 =( 9.75 in)( 4.2 in) = 40.95 in 2 A Nc3 =( 3.8 in + 3.4 in)( 9.75 in) = 70.2 in 2 A Nc4 =( 9.75 in + 2.6 in)( 9.675 in) = 119.49 in 2 A Nc5 =( 3.4 in)( 2.125 in) = 7.23 in 2 A Nc6 =( 11.55 in)( 3.2 in) = 36.96 in 2
ACI 318-19 Fig. R17.6.2.1 b)
NOTE:
• anchors are color coded
• 1.5h ef projected from each anchor is color coded
• 1.5h ef is projected in x +, x-, y + and y- direction from center of each anchor
• Projection from anchors 5 and 6 in y- direction limited by 3.2 in edge distance
A Nc = 297.51 in 2 A Nc0 = 9( h ef) 2 = 9( 3.25 in) 2 = 95.06 in 2 ACI 318-19 Eq.( 17.6.2.1.4)
ψ ec, N =
1 1 + e ′ N
1.5h e f
ACI 318-19 Eq.( 17.6.2.3.1) e c1, N = 0.467 in e c2, N = 0.1 in 1.5h ef = 4.875 in ψ ec, N =( ψ ec1, N)( ψ ec2, N) = 0.895
ψ ed, N = 0.7 + 0.3 c a, min 1.5h e f
= 0.897 ψ ec1, N = 0.913 ψ ec2, N = 0.98 ACI 318-19 Eq.( 17.6.2.4.1b) c a, min = c y- = 3.2 in 1.5h ef = 4.875 in ψ c, N = 1.0 cracked or uncracked concrete Reference ACI 318-19 17.6.2.5.1
ψ cp, N = MAX c a, min | 1. 5h e f
= 1.0 cracked concrete Reference ACI 318-19 17.6.2.6.1. c ac c ac
ACI 318-19 Eq.( 17.6.2.2.1)
N b = k c, xxxx λ a f ′ c h e f
1.5 normal weight concrete: λa = 1.0
N b =( 17)( 1.0)( 3000 psi) 0. 5( 3.25 in) 1. 5 = 5456 lb λ a: reference ACI 318-19 Table 17.2.4.1 k c, cr = 17 Reference ESR-4266 Table 4
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|
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f ' c = 3000 psi h ef = 3.25 in |
N cbg = |
A Nc A Nc0 |
ψ ec, N ψ ed, N ψ c, N ψ cp, N N b |
A Nc = 297.51 in 2 A Nc0 = 95.06 in 2 |
N cbg =( 297.51 in 2 / 95.06 in 2)( 0.895)( 0.897)( 1.0)( 1.0)( 5456 lb) ψ ec, N = 0.895 ψ ed, N = 0.897 ψ c, N = 1.0 ψ cp, N = 1.0 N b = 5456 lb
= 13,709 lb
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